Extensile – Robotic Fabrication Workshop / CAAD ETHz

Extensile is the product of a 2 week intensive workshop, given at the MAS students of the Chair for Computer Aided Architectural design, ETH Zurich. The two main purposes of the project were to get students familiar with using the robot, and devising a robotic fabrication method that was innovative.

The production method we proposed, was therefore neither subtractive nor additive, but could rather be described as “formative”. It suggested the use of thermoplastic, a polymer which becomes pliable above a specific temperature and again solidifies when cooled down. For this, we created a setup in which the plastic sheet was fixed on a wooden frame mounted on the robot. A heat gun and a formative tool-tip were placed on the floor. The procedure had the robot moving the polymer sheet on top of the heat gun, where it was locally heated for a specific amount of time, and then pushed over the tool-tip which was functioning as a mold, deforming the pliable area.

During the workshop, a wide array of tests were done to experiment with different 3D-printed tool-tips, formation heights, angles and densities in relation to heating durations. Eventually, the study of the material’s capabilities and the formalization and correlation of the aforementioned parameters, resulted in parametric tools that assisted the material-specific design process and automated the fabrication procedure. The former study results, in conjunction with the use of a 7-axis Kuka robot, allowed us to design and fabricate with a high degree of controlled variation, on the tolerance limits of our material.

The students developed an idea for a panelled construction, of 4×8 40×40 cm modules. It’s design was produced by a combination of Wolfram Mathematica and Grasshopper, and the design tool developed, generated material-optimised geometry from a complex system that was manipulating probabilistic mathematical distributions. The robot code was exported using the KUKA|prc Grasshopper plug-in.

Extensile was presented at the Chair for Computer Aided Architectural Design on 11/06/2015